main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".ui.main.MainActivity">

    <android.support.v7.widget.CardView
        android:id="@+id/card_news"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:clickable="true"
        android:focusable="true"
        android:foreground="?attr/selectableItemBackground"
        app:layout_constraintBottom_toTopOf="@+id/card_search"
        app:layout_constraintEnd_toStartOf="@+id/card_archive"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <FrameLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@color/colorRed">

            <TextView
                android:id="@+id/txt_main_news"
                style="@style/MainMenuTextView"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:drawableTop="@drawable/ic_format_list_bulleted_white_48dp"
                android:text="@string/main_menu_news" />

        </FrameLayout>
    </android.support.v7.widget.CardView>

    <android.support.v7.widget.CardView
        android:id="@+id/card_archive"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginTop="8dp"
        android:clickable="true"
        android:focusable="true"
        android:foreground="?attr/selectableItemBackground"
        app:layout_constraintBottom_toTopOf="@+id/card_settings"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintStart_toEndOf="@+id/card_news"
        app:layout_constraintTop_toTopOf="parent">

        <FrameLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@color/colorBlue">

            <TextView
                android:id="@+id/txt_main_archive"
                style="@style/MainMenuTextView"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:drawableTop="@drawable/ic_bookmark_border_white_48dp"
                android:text="@string/main_menu_archive" />

        </FrameLayout>
    </android.support.v7.widget.CardView>

    <android.support.v7.widget.CardView
        android:id="@+id/card_search"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginStart="8dp"
        android:clickable="true"
        android:focusable="true"
        android:foreground="?attr/selectableItemBackground"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toStartOf="@+id/card_settings"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/card_news">

        <FrameLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@color/colorGreen">

            <TextView
                android:id="@+id/txt_main_search"
                style="@style/MainMenuTextView"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:drawableTop="@drawable/ic_search_white_48dp"
                android:text="@string/main_menu_search" />

        </FrameLayout>
    </android.support.v7.widget.CardView>

    <android.support.v7.widget.CardView
        android:id="@+id/card_settings"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginRight="8dp"
        android:clickable="true"
        android:focusable="true"
        android:foreground="?attr/selectableItemBackground"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintStart_toEndOf="@+id/card_search"
        app:layout_constraintTop_toBottomOf="@+id/card_archive">

        <FrameLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@color/colorYellow">

            <TextView
                android:id="@+id/txt_main_settings"
                style="@style/MainMenuTextView"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:drawableTop="@drawable/ic_tune_white_48dp"
                android:text="@string/main_menu_settings" />

        </FrameLayout>
    </android.support.v7.widget.CardView>
</android.support.constraint.ConstraintLayout>

<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <!-- Customize your theme here. -->
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
</style>

<style name="RedTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <!-- Customize your theme here. -->
    <item name="colorPrimary">@color/colorRed</item>
    <item name="colorPrimaryDark">@color/colorRedDark</item>
    <item name="colorAccent">@color/colorAccent</item>
</style>

<style name="GreenTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <!-- Customize your theme here. -->
    <item name="colorPrimary">@color/colorGreen</item>
    <item name="colorPrimaryDark">@color/colorGreenDark</item>
    <item name="colorAccent">@color/colorGreen</item>
</style>

<style name="BlueTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <!-- Customize your theme here. -->
    <item name="colorPrimary">@color/colorBlue</item>
    <item name="colorPrimaryDark">@color/colorBlueDark</item>
    <item name="colorAccent">@color/colorBlue</item>
</style>

<style name="MainMenuTextView">
    <item name="android:textColor">#FFFFFF</item>
    <item name="android:textAllCaps">true</item>
    <item name="android:textSize">18sp</item>
    <item name="android:layout_gravity">center</item>
</style>

<style name="SelectableItemTheme">
    <item name="colorControlHighlight">@color/colorPrimaryDark</item>
</style>

<style name="SelectableItemBackground">
    <item name="android:theme">@style/SelectableItemTheme</item>
    <item name="android:background">?attr/selectableItemBackground</item>
</style>

<style name="FullscreenTheme" parent="AppTheme">
    <item name="android:windowActionBarOverlay">true</item>
    <item name="android:windowBackground">@null</item>
    <item name="metaButtonBarStyle">?android:attr/buttonBarStyle</item>
    <item name="metaButtonBarButtonStyle">?android:attr/buttonBarButtonStyle</item>
</style>

#808080 #4d4d4d #D32F2F

<color name="colorTextPrimary">#212121</color>
<color name="colorTextSecondary">#757575</color>
<color name="colorYellow">#FFC107</color>
<color name="colorYellowDark">#FFA000</color>
<color name="colorGreen">#4CAF50</color>
<color name="colorGreenDark">#388E3C</color>
<color name="colorBlue">#536DFE</color>
<color name="colorBlueDark">#303F9F</color>
<color name="colorRed">#D32F2F</color>
<color name="colorRedDark">#a00c0c</color>

News Digest News Digest - Archive ArticleActivity News Digest - Search News Digest - Sources

<string name="action_menu_search">Search</string>
<string name="action_menu_clear">Clear</string>
<string name="action_menu_archive">Go to Archive</string>
<string name="action_yes">Yes</string>
<string name="action_no">No</string>
<string name="action_undo">Undo</string>
<string name="msg_clear">Are you sure you want to delete all archived articles?</string>
<string name="msg_removed">Article removed.</string>
<string name="msg_archived">Article archived.</string>
<string name="msg_already_archived">Already in archive!</string>
<string name="main_menu_settings">Settings</string>
<string name="main_menu_search">Search</string>
<string name="main_menu_archive">Archive</string>
<string name="main_menu_news">News</string>
<string name="hint_query">Enter query…</string>
<string name="msg_query_short">query too short!</string>
<string name="sources_category">Category:</string>
<string name="error_network">Error! Please check your network connection.</string>
<string name="title_dialog">Caution!</string>